Arrangement for injection nozzle and exhaust openings in a diesel assisted ram

ABSTRACT

A diesel assisted pile driver, having a cylinder in which a percussion piece and a piston are arranged and a metering pump having a nozzle delivers a stream of fuel on the surface of the percussion piece. Openings for the exhaust of burnt gas is provided and the exhaust openings lie entirely in that half of the cylinder wall opposite to that in which the fuel injector nozzle lies. Preferably two openings are provided lying symmetrical to a vertical diametric plane in which the injector nozzle lies.

Hennecke et al.

ARRANGEMENT FOR INJECTION NOZZLE AND EXHAUST OPENINGS IN A DIESEL ASSISTED RAM Inventors: Rudolf Hennecke, Buoch; Fritz Kommel, Esslingen (Neckar); Albert Haussmann, Oberboihingen, all of Germany Appl. No.: 503,351

Related US. Application Data Continuation of Ser. No. 303,394, Nov. 3, 1972, abandoned.

Foreign Application Priority Data Nov. 6, 1971 Germany 2155306 US. Cl. 123/32 R; 173/134 Int. Cl. F02D 3/00 1 1 Dec. 2, 1975 [58] Field of Search 123/32 R; 173/134 [56] References Cited UNITED STATES PATENTS 2.740.385 4/1956 Haagc 123/32 R 2,838,032 6/1958 Schulin ct a1. .1 173/134 Primary Examiner-Wendell E. Burns Assistant Examiner-James Winthrop Cranson, Jr.

[57] ABSTRACT A diesel assisted pile driver, having a cylinder in which a percussion piece and a piston are arranged and a metering pump having a nozzle delivers a stream of fuel on the surface of the percussion piece. Openings for the exhaust of burnt gas is provided and the exhaust openings lie entirely in that half of the cylinder wall opposite to that in which the fuel injector nozzle lies. Preferably two openings are provided lying symmetrical to a vertical diametric plane in which the injector nozzle lies.

4 Claims, 3 Drawing Figures US. Patsnt Dec. 2, 1975 ARRANGEMENT FOR INJECTION NOZZLE AND EXHAUST OPENINGS IN A DIESEL ASSISTED RAM This is a continuation application of Ser. No. 303,394, filed Nov. 3, 1972, now abandoned.

The present invention relates to a diesel-assisted type ram or pile driver and in particular to an arrangement for the injection nozzle and exhaust opening.

Diesel-assisted or internal combustion assisted pile drivers, hammers, or the like (the terms are used interchangeably) are well known. Briefly, such apparatus comprises a housing mounted to be adjustable and/r movable on a vertical standard or scaffold. The housing defines a ram cylinder having a percussion piece at one end adapted to strike the pile or other work piece and ram piston movable to strike the percussion piece. The ram piston is generally lifted by a hoist or other pulley system and allowed to drop on the percussion piece. In diesel-assisted rams of this type, a combustion fuel is sprayed into the cylinder and is compressed and atomized on impact by the downwardly moving ram piston until it explodes. The explosion forces the percussion piece with greater force on the pile or workpiece while simultaneously lifting the ram piston upwardly, preparatory to another cycle. In order to facilitate such atomization there is provided in German Pat. No. 2,040,924, Appl. P. 2040924.9-25the technique of forming the abutting or striking faces of the piston and percussion head with flat planar surfaces.

Generally, the fuel is injected into the ram cylinder by a spray nozzle mounted in the cylinder wall of the ram. The wall is also provided about its circumference with several uniformly arranged openings or ports which serve both as inlets for fresh air and exhaust outlets for the combusted fuel. In the known devices, which were dependent upon the atomization of the fuel, it is most desirable that the entire volume of fuel sprayed into the cylinder be deposited on the face of the percussion piece in order to obtain the maximum explosion on ram stroke. That portion of the fuel which does, however, become deposited on the walls of the cylinder does not split or atomize, but only burns slowly. This results in the creation of smoke and soot and undesirable afterburning effects. On the other hand, a quick instantaneous explosion is required of the fuel in order to obtain a full high piston stroke. Therefore, the fuel which is normally deposited on the cylinder wall must be effectively brought into the explosive action of the ram.

In the known rams of the diesel type in which there is arranged plural inlet and outlet openings around the circumference of the cylinder the falling piston causes the burned gases to be, in practice, compressed uniformly along the entire length of the cylinder from the top to the exhaust openings. As a result there is created a stream of burned gases acting in a contra-direction and in opposition to the direction of injected spray of fuel. In this connection it is to be noted that diesel rams of this type, because of structural requirements, require that the highest proportion of fuel be injected at an early stage of the cycle; that is, before the piston reaches and covers the exhaust openings. This fuel stream may. be deformed and caused to flutter or stray, by the contrary directed effluent exhaust stream so that the fuel is deflected from the center of the face of the percussion piece and undesirably wets the side walls of the cylinder. This problem is not only critical with percussion faces that are planar or flat but is also critical in those devices in which the faces are concave or cup shaped.

It is the object of the present invention to provide a diesel type ram which overcomes the difficulties and disadvantages of the prior art.

According to the present invention a diesel type ram is provided in which the combustion fuel is more completely than heretofore sprayed directly on the surface of the percussion piece, which surface forms the floor or base of the combustion chamber and which more than heretofore avoids the wetting and deposition of fuel on the walls of the cylinder.

Contrary to theknown devices wherein the diesel ram is provided with a fuel injector and with an inlet and gas exhaust openings arranged uniformly about the central axis of the cylinder, the present invention provides that the inlet/outlet openings are combined and are arranged entirely in that half of the cylinder wall lying opposite to the half in which the injector spray nozzle is located. Thus, the arrangement results in the formation of .a steady stream of fuel injected into the cylinder and onto the percussion piece. Even on the falling of the ram piston there is created a gas exhaust stream having a direction which is the same as that of the injected fuel itself. Also, as a result of this construction, the ramipiston forces the gas exhaust beneath the incoming fuel stream and directly upward out of the oppositely lying exhaust opening in a stream independent of the incoming fuel stream. In this manner, the injected fuel stream remains cohesive and collected together until deposition on the surface of the percussion piece.

The exhaust openings may be plural but must lie approximately opposite to the fuel injection nozzle to either side of a plane corresponding to the vertical projection thereof, but need not be dependent, however, by the height of the nozzle, or exhaust openings. Instead of several exhaust openings only one large opening may be provided which may be correspondingly dimensioned in the cylinder wall, opposite to the spray nozzle.

Practical experiments have shown that very advantageous results are obtained when'two openings are provided, arranged in the opposite wall symmetrically with respect to the vertical diametn'c plane in which the fuel injection nozzle lies.

Full details and advantages of the present invention will be seen from .the following description and the accompanying drawings.

In the drawings:

FIG. 1 is a vertical side view of a diesel ram mounted on a supporting scaffold;

FIG. 2 is an enlarged view in section of the area of FIG. 1 defined by the circle A; and

FIG. 3 is a sectional view through line 3-3 of FIG. 2.

Before turning to the description of the preferred embodiment of this invention, reference is made and incorporation made of copending applications of the common assignee, Ser. No. 3,303,397 and Ser. No. 3,303,395, both filed on even date hereof, corresponding respectively to German applications P 2155310.6 and G 71420343 which show other aspects of a ram or pile driver of the type here under discussion. Reference may also be made to the application of Rudolf Hennecke et al. US. Ser. No. 258,896, filed June 1, 1972, as well as to German Patents 2,040,924, and 7,030,915.

While in general, the present invention may be applied to conventional apparatus of type earlier described, reference can be made to the above for any other details not deemed necessary to be described herein.

In FIG. 1 there is seen a vertical tubular supporting standard 10, on which is movably mounted a diesel type ram 12. The ram comprises an upper section 14, a mid-section l6 and a lower cylinder section 18 which are joined together in end to end relationship. Guide jaws (brackets) 20 for guiding the ram on the tubular standard are mounted on each of the last two named sections. A fuel injection pump 22 is mounted on the lower section 18 and inlet/exhaust openings 24 are also provided in the lower section 18. Only one such inlet/- outlet opening is seen in FIG. 1 although several maybe provided. The exhaust openings 24 serve not only to expell the burned gases of combustion but also to suck in fresh air during the respective stages of operation. The lower section 18 houses a so-called percussion piece 26 which is guided for movement in a defined vertical path, onto the pile or work piece.

The present invention as applied to the diesel type ram is clearly seen in FIGS. 2 and 3, which show a portion of the cylinder wall 30, the slot about which the fuel injection pump 22 is fastenedand one of the inlet- /exhaust openings 24. FIG. 2 shows also the piston 32 and the upper portion of the percussion piece 26. The cooperative striking faces of the piston 32 and the percussion piece 26 are indicated by the numerals 34 and 36 respectively and may be either flat and planar, or cup-shaped.

The fuel injection pump 22 by which fuel is closed or matered to the cylinder is activated by a lever 40 pivoted about an axis 38, which is engaged by the piston 32 as the piston is caused to fall. The fuel pump can be made in any conventionally desirable form, and need not be described any further herein. Reference, however, can be made to copending applications referred to earlier.

The fuel pump comprises a spray nozzle 42 which injects a stream of combustion fluid shown by the dotdash lines 44 directly into the cylinder chamber 46 and as is most desirable directly on to the striking face 36 of the percussion piece 26 so that it fully strikes the head to become atomized into minute particles thereon. For this purpose, the spray nozzle 42 is so arranged and positioned that the fuel stream 44 is directed substantially at the center of the face 36, as indicated by the axial line through the center of the cylinder 18.

The fuel injection pump 42 lies opposite to two inletlexhaust openings 24 which are spaced from each other, as seen in FIG. 3, and lie uniformly and symmetrically to either side of the vertical diametric plane passing through the center of the cylinder and as defined by the path 44 of the fuel injected by the spray nozzle 42. Preferably, the distance between each of the exhaust openings comprises an angle of 90 while the distance between the spray nozzle and each of the openings 24 is greater, being approximately 135. It will thus be seen that if a diametrical plane were drawn, perpendicular to the plane defined by the line of fuel spray 44, that the inlet/exhaust openings will lie in that half of the circle (in cross section) of the cylinder opposite to that of the nozzle 42. In the axial direction the exhaust openings 24 extend at an upward angle, the inner end being below the level of the spray nozzle 42.

The above described arrangement operates in the following manner:

On the falling of the ram piston 32 in its free fall down stroke, the ram piston at first forces the burned gases of the previous explosion, ahead of it, and because the exhaust openings lie opposite to the spray nozzle creates a stream or flow of gas shown by arrow B in FIG. 2.

The fuel is sprayed or injected before the piston moves past the opening 24 and so the nozzle is situated higher than the exhaust opening and therefore establishes its path before the effluent gas stream is stopped. The exiting gas stream B is only directed downwardly in the direction of the fuel stream on that side of the cylinder below the nozzle so that it moves in the same direction as the stream 44, while on the opposite side it moves directly upward toward the exit. Thus the effluent gas stream can not negatively effect the incoming fuel stream. This prevents the fuel from scattering and wetting the cylinder wall and insures that the entire fuel accumulates on the face 36 of the percussion piece and atomizes and bursts open on the downward movement of the ram piston.

It will be appreciated that more or less than the two exhaust openings can be provided, however, it is to be noted that they should be arranged in such a manner opposite to the injected fuel spray and fuel stream that they provide practically no contrary directed exhaust gas stream.

It will thus be seen that by locating the nozzle and the inlet exhaust openings as indicated herein, two independent, non-conflicting paths for the fuel and exhaust gas respectively is provided. Moistening of the side walls is prevented, and deflection of the injected stream is obviated.

The present disclosure is intended to be illustrative only of the invention and not limiting of its scope.

What is claimed:

1. A diesel-assisted ram, pile driver or the like having a cylinder in which a percussion piece and a piston adapted to impact thereon are arranged, a metering pump having a fuel injector nozzle for delivery of a stream of fuel on the surface of the percussion piece, said fuel atomizing on impact of said piston on said percussion piece, said cylinder having a plurality of openings for exhaust of gas and for the intake of air being closed and opened by movement of the piston, and being open at least during part of the fuel delivery, said openings lying entirely in that half of the cylinder wall opposite to that in which the fuel injector nozzle lies.;

2. The ram according to claim 1 in which two open ings are provided lying symmetrical to a vertical diametric plane in which the injector nozzle lies.

3. The ram according to claim 1, wherein said percussion piece and said piston have planar impact surfaces.

4. A diesel-assisted ram, pile drive or the like having a cylinder in which a percussion piece and a piston adapted to impact thereon are arranged, a metering pump having a fuel injector nozzle for delivery of a strarn of fuel on the surface of the percussion piece, said fuel atomizing on impact of said piston on said percussion piece, said cylinder having a single opening for the exhaust of gas and for the intake of air, said single of the cylinder wall opposite to that in which the fuel opening being closed and opened by movement of the injector nozzle lies along a line substantially diametripiston, and being open at least during part of the fuel cally opposite to the line on which said nozzle lies. delivery, said single opening lying entirely in that half 

1. A diesel-assisted ram, pile driver or the like having a cylinder in which a percussion piece and a piston adapted to impact thereon are arranged, a metering pump having a fuel injector nozzle for delivery of a stream of fuel on the surface of the percussion piece, said fuel atomizing on impact of said piston on said percussion piece, said cylinder having a plurality of openings for exhaust of gas and for the intake of air being closed and opened by movement of the piston, and being open at least during part of the fuel delivery, said openings lying entirely in that half of the cylinder wall opposite to that in which the fuel injector nozzle lies.
 2. The ram according to claim 1 in which two openings are provided lying symmetrical to a vertical diametric plane in which the injector nozzle lies.
 3. The ram according to claim 1, wherein said percussion piece and said piston have planar impact surfaces.
 4. A diesel-assisted ram, pile drive or the like having a cylinder in which a percussion piece and a piston adapted to impact thereon are arranged, a metering pump having a fuel injector nozzle for delivery of a stram of fuel on the surface of the percussion piece, said fuel atomizing on impact of said piston on said percussion piece, said cylinder having a single opening for the exhaust of gas and for the intake of air, said single opening being closed and opened by movement of the piston, and being open at least during part of the fuel delivery, said single opening lying entirely in that half of the cylinder wall opposite to that in which the fuel injector nozzle lies along a line substantially diametrically opposite to the line on which said nozzle lies. 